Field of study variation throughout the college pipeline and its effect on the earnings gap: Differences between ethnic and immigrant groups in Israel

This study demonstrates the analytical leverage gained from considering the entire college pipeline—including the application, admission and graduation stages—in examining the economic position of various groups upon labor market entry. The findings, based on data from three elite universities in Israel, reveal that the process that shapes economic inequality between different ethnic and immigrant groups is not necessarily cumulative. Field of study stratification does not expand systematically from stage to stage and the position of groups on the field of study hierarchy at each stage is not entirely explained by academic preparation. Differential selection and attrition processes, as well as ambition and aspirations, also shape the position of ethnic groups in the earnings hierarchy and generate a non-cumulative pattern. These findings suggest that a cross-sectional assessment of field of study inequality at the graduation stage can generate misleading conclusions about group-based economic inequality among workers with a bachelor’s degree.     

烹调油烟的免疫毒理学研究进展

烹调油烟是室内主要空气污染物之一，化学成分复杂，严重影响职业接触人群的健康．对烹调油烟免疫毒性的研究是全面评价其毒性作用的一个重要方面．对近几年来烹调油烟影响机体细胞免疫、体液免疫和巨噬细胞以及NK细胞功能等免疫毒性方面的研究进展作一综述．     

Olive Oil Consumption in Greece: A Microeconometric Analysis

In this paper, the factors affecting at-home demand for three types of oils and fats in Greece, with emphasis on olive oil, are investigated using the linear approximation of the Almost Ideal Demand System and family budget survey data. To overcome the econometric problem created with the existence of zero expenditure, a generalization of the two-stage Heckman procedure is employed. In order to investigate the role of self-consumption, two different samples were used. The first includes all households; the second excludes those that acquire olive oil only from own production. According to the results, there are important differences in the first stage of the decision process between the two samples. Unlike the first stage, the second stage of the decision process found no important differences between the results for the two samples.     

西气东输工程对中西部地区经济与社会协调发展效益考查

和谐社会的构建,其核心是经济和社会的协调发展,而区域经济的协调发展是实现我国经济与社会协调发展必须解决的问题。针对改革中出现的区域差距不断扩大的趋势,党中央适时地提出了西部大开发战略。西气东输工程是实施西部大开发的标志性工程,它的建设有效地促进了中西部地区经济和社会的协调发展,对于促进东中西三类地区社会的整体进步和稳定以及加快我国和谐社会建设的进程具有重要的意义。     

石油企业建立岗效薪点工资制的探索 --以胜利油田为例的研究

从建立油田有限公司基本工资制度的角度出发，分析了岗效薪点工资制的地位、作用及局限性；提出了完善该工资制的具体建议。     

关于改进我国天然气管输定价方式的探讨

探索了我国现行天然气管输运价形成机制严重背离天然气市场发育的弊端，进而提出与国际接轨的建议，即通过分别确定管输企业年度应收服务费和按两部制设计用户运价率来制定管输价格。     

钢管相邻缺陷漏磁场相互影响的分析

实际工况中的管道缺陷是非常复杂的,用物理试验的方法研究各种缺陷漏磁场的变化规律有一定的难度。该文针对油气管道常用的钢管缺陷产生的漏磁场建立了三维有限元模型,采用有限元方法计算了几种相邻缺陷的漏磁场模型,给出了计算结果,并分析了各种相邻缺陷对漏磁场信号的影响。结果表明当相邻缺陷的中心线与磁场方向平行时,对缺陷漏磁信号的影响最小;组合型的缺陷对漏磁信号的影响最大。     

泡沫增强聚合物体系配方研究

在分析了聚合物驱提高采收率技术在实际应用中的局限性基础上,提出了采用就地起泡形成泡沫的泡沫增强聚合物体系以减小聚合物沿大通道窜流的问题。为了有效确定该体系的配方,实验中采用了均匀设计实验方法安排实验,并运用DPS数据处理软件对实验数据进行了二次多项式逐步回归处理,找出了影响该体系性能的主要因素。     

等温输油管线设计技术经济分析

本文从费用最省的角度出发,建立了计算等温输油管线最优技术参数的数学模型,并给出了数学模型的求解方法。